The present disclosure relates to a light emitting device, a light emitting device package, and a lighting system.
Due to physical and chemical characteristics, group III-V nitride semiconductors are being considered as core materials for light-emitting devices such as light-emitting diodes (LEDs) and laser diodes (LDs). Generally, group III-V nitride semiconductors are formed of a semiconductor material having a compositional formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1).
LEDs are a kind of semiconductor device that is used as a light source or uses the characteristics of compound semiconductors to convert electricity into infrared rays or light, thereby receiving or transmitting signals.
These semiconductor based LEDs or LDs are widely used in light-emitting devices, and are applied as light sources for various products such as keypad light-emitting units of mobile phones, electric light panels, and illumination devices.